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| United States Patent |
5,236,949
|
|
Nair
|
August 17, 1993
|
Method for controlling insects
Abstract
A method for controlling insects using nitrophenyl pyrones is described.
The pyrones are preferably derived from Streptomyces sp. by a method
involving growth and extraction of the pyrones. A novel pyrone, griseulin
is also described.
| Inventors:
|
Nair; Muraleedharan G. (Okemos, MI)
|
| Assignee:
|
Board of Trustees operating Michigan State University (East Lansing, MI)
|
| Appl. No.:
|
011512 |
| Filed:
|
February 1, 1993 |
| Current U.S. Class: |
514/459 |
| Intern'l Class: |
A01N 043/16 |
| Field of Search: |
514/459
|
References Cited
U.S. Patent Documents
| 3116202 | Dec., 1963 | Dietz et al. | 167/65.
|
| 4225674 | Sep., 1980 | Celmer et al. | 435/122.
|
| 4247462 | Jan., 1981 | Celmer et al. | 260/239.
|
Other References
Hirata, Y., et al., Tet. Let. 14 252-254 (1961).
Yamazaki, M., et al., Tet. Let. 26 2701-2704 (1972).
Kakinuma, K., et al., Tetrahedron 217-222 (1976).
Koyama, Y., et al., Tet. Let. 5 355-358 (1969).
|
Primary Examiner: Robinson; Allen J.
Attorney, Agent or Firm: McLeod; Ian C.
Parent Case Text
CROSS-REFERENCED TO RELATED APPLICATIONS
This is a divisional of copending application Ser. No. 07/811,950 filed on
Dec. 23, 1991, which is a continuation-in-part of application Ser. No.
07/177,311, filed Apr. 5, 1988 now abandoned.
Claims
I claim:
1. A method for killing an insect which comprises exposing the insect to an
effective amount of
##STR6##
wherein x is an integer between 0 and 8 and R is selected from the group
consisting of a direct bond, --CH.dbd.CH-- and --CH.dbd. furanyl.
2. The method of claim 1 wherein the pyrone is
##STR7##
3. The method of claim 1 wherein the pyrone is a
##STR8##
4. The method of claim 1 wherein the pyrone is a
##STR9##
5. The method of claim 1 wherein the pyrone is
##STR10##
6. The method of claim 1 wherein the nitrophenyl pyrone is selected from
the group consisting of
##STR11##
7. The method of claim 1 wherein the insect is exposed to an amount between
about 0.001 and 100 ppm by weight of the compound.
8. A method for killing an insect which comprises exposing the insect to an
effective amount of a compound selected from the group consisting of
spectinabilin, aureothin, luteoreticulin, griseulin and isomers thereof to
kill the insect.
9. The method of claim 8 wherein the compound is spectinabilin.
10. The method of claim 8 wherein the insect is in a soil.
11. The method of claim 8 wherein the insect is mosquito larvae.
12. The method of claim 11 wherein the mosquito larvae is Aedes egyptii.
13. The method of claim 12 wherein the larvae are dispersed in a pool of
water to which the compound is applied.
14. The method of claim 8 wherein the insect is exposed to an amount
between about 0.001 and 100 ppm by weight of the compound.
Description
BACKGROUND OF THE INVENTION
(1) Field of the Invention
The present invention relates to a method for controlling pests wherein the
insect is exposed to a pyrone containing a nitrophenyl group. The
compounds are particularly effective against nematodes and mosquito
larvae.
(2) Prior Art
Many nitrophenyl pyrones of the present invention are known compounds.
Aureothin is described by Hirata, Y., et al., Tet. Let. 14 252-254 (1961)
and Yamazaki, M., et al., Tet. Let. 26 2701-2704 (1972). Spectinabilin is
described by Kakinuma, K, et al Tetrahedron 217-222 (1976) as having
antibacterial activity. Luteoreticulin is described by Kovama, Y, et al.,
Tet. Let. 5 355-358 (1969).
U.S. Pat. Nos. 3,116,202 to Dietz et al 4,225,674 to Celmer et al and
4,247,462 to Celmer et al describe species of Streptomyces which produce a
streptovaricin, an antibacterial compound. It is known that these fungi
can produce other compounds besides the ansamycin antibacterial. Thus,
Kakinuma et al Tetrahedron (1976) showed that spectinabilin is produced by
the same strain which produces the streptovaricin antibiotics.
The problem faced by the prior art is to provide potent insecticidal
compounds which are effective at low dosages.
OBJECTS
It is therefore an object of the present invention to provide a
particularly effective method for controlling insects. It is further an
object to provide a method which requires low dosages of the insecticidal
compounds and thus is economical. These and other objects will become
increasingly apparent by reference to the following description and the
drawings.
IN THE DRAWINGS
FIG. 1 is a diagram showing the sequence for the extraction of the
nitrophenyl pyrones of Examples 1 to 4.
FIGS. 2 to 5 are .sup.1 H-NMR spectra for the nitrophenyl pyrones of
Examples 1 to 4.
FIGS. 6 to 9 are .sup.13 C-NMR spectra for the nitrophenyl pyrones of
Examples 1 to 4.
FIGS. 10 to 13 are ultraviolet spectra for the nitrophenyl pyrones of
Examples 1 to 4.
FIGS. 14 to 17 are the mass spectra for the nitrophenyl pyrones of Examples
1 to 4.
GENERAL DESCRIPTION
The present invention relates to a method for controlling an insect which
comprises exposing the insect to an effective amount of
##STR1##
wherein x is an integer between 0 and 8 and R is selected from the group
consisting of a direct bond, --CH.dbd.CH-- and --CH.dbd. cyclic
substituents containing 5 to 6 carbon atoms.
In particular the present invention relates to a method for controlling an
insect which comprises exposing the insect to an effective amount of a
compound selected from the group consisting of spectinabilins, aureothin,
luteoreticulin, griseulin and isomers thereof produced by a Streptomyces
sp..
Further, the present invention relates to the a composition for controlling
insects which comprises:
(a)
##STR2##
nitrophenyl pyrone wherein x is an integer between 0 and 8 and wherein R
is selected from the group consisting of a direct bond, --CH.dbd.CH-- and
--CH.dbd. cyclic substituents containing 5 to 6 carbon atoms; and
(b) an agricultural carrier other than water alone, wherein the nitrophenyl
pyrone is present in an amount between about 0.001 and 100 ppm in the
carrier sufficient to control the insect.
In particular the present invention relates to a composition for
controlling insects which comprises:
(a) a compound selected from the group consisting of spectinabilins,
aureothin, luteoreticulin and griseulin and isomers thereof; and
(b) an agricultural carrier other than water alone, wherein the aureothin
is present in an amount between about. 0.001 and 100 ppm in the carrier
sufficient to control the insect.
Finally the present invention relates to a novel compound of the formula
##STR3##
The nitrophenyl pyrones of the present invention are particularly effective
against nematodes and mosquito larvae which are traditionally very
difficult to kill. They can also be useful against other insects. The
nitrophenyl pyrones of the present invention are particularly used in
amounts between about 0.001 and 100 ppm which are insecticidally
effective.
The nitrophenyl pyrone can be applied to the plant material, e.g. either to
the seed or a propagule. Preferably the nitrophenyl pyrone is coated on
the seed using an adhesive such as methyl cellulose, which is compatible
with plant growth. The nitrophenyl pyrone can also be impregnated into the
seed.
The nitrophenyl pyrone can be applied in a liquid agricultural carrier with
a dispersant which maintains the nitrophenyl pyrone in solution in an
amount between about 0.001 and 100 micrograms per ml to deliver about
0.001 and 100 ppm to the insect. Preferred dispersants are lower alkanols,
particularly methanol, with various surfactants including anionic and
cationic surfactants. Other organic solvents can be used to form emulsions
of the nitrophenyl pyrone in water. The nitrophenyl pyrones can be
provided in a solid mixture including the dispersant and the nitrophenyl
pyrone. The composition can be formulated in solid carriers which aid in
dispersing the nitrophenyl pyrone in the soil or planting material. The
nitrophenyl pyrone is present in an amount in the solid carrier which
provides between about 1 and 100 micrograms by weight of the solid
carrier.
The nitrophenyl pyrones can be formulated as wettable powders, flow
concentrates, emulsifiable concentrates, granular formulations and the
like.
Wettable powders can be prepared by grinding together about 20% to 45% by
weight of a finely divided carrier such as kaolin, bentonite, diatomaceous
earth, attapulgite, or the like, 45% to 80% by weight of the nitrophenyl
pyrone, 2% to 5% by weight of a dispersing agent such as sodium
lignosulfonate, and 2% to 5% by weight of a nonionic surfactant, such as
octylphenoxy polyethoxy ethanol, nonylphenoxy polyethoxy ethanol or the
like.
A typical flowable liquid can be prepared by admixing about.40% by weight
of the nitrophenyl pyrone with about 2% by weight of a gelling agent such
as bentonite, 3% by weight of a dispersing agent such as sodium
lignosulfonate, 1% by weight of polyethylene glycol and 54% by weight of
water.
A typical emulsifiable concentrate can be prepared by dissolving about 5%
to 25% by weight of the active ingredient in about 65% to 90% by weight of
N-methyl-pyrrolidone, isophorone, butyl cellosolve, methylacetate or the
like and dispersing therein about 5% to 10% by weight of a nonionic
surfactant such as an alkylphenoxy polyethoxy alcohol. This concentrate is
dispersed in water for application as a liquid spray.
When the nitrophenyl pyrones are used for soil treatment, the compounds may
be prepared and applied as granular products. Preparation of the granular
product can be achieved by dissolving the nitrophenyl pyrone in a solvent
such as methylene chloride, N-methylpyrrolidone or the like and spraying
the thus prepared solution on a granular carrier such as corncob grits,
sand, attapulgite, kaolin or the like.
The granular product thus prepared generally comprises about 3% to 20% by
weight of nitrophenyl pyrone and about 97% to 80% by weight of the
granular carrier. The nitrophenyl pyrones can also be mixed with herbicide
or other pesticides which are applied to the plants or applied before or
after the application of the herbicide or pesticide.
The Streptomyces strains used in the present invention are available from
the American Type Culture Collection. They have been deposited by third
parties and are available upon request. Numerous such strains are
available from the ATCC and can be tested for the production of the
nitrophenyl pyrones which are a distinct class of compounds. Streptomyces
griseus var autotrophicus has been deposited as ATCC 53668 and produces
compounds MN-2-147A and griseulin, a novel nitrophenyl pyrone, and
aureothin, described hereinafter (Table 1). The strain produces
faeriefungin as described in U.S. application Ser. No. 07/177,311.
Isolation and Growth. ATCC 53668 was isolated from a soil sample collected
from the center of a fairy ring. The soil was suspended in sterile
physiological saline and serial dilutions were plated on various isolation
media. The colony of this strain was picked up from a Czapeck agar plate
(sucrose 20.0 g, NaNO.sub.3 3.0 g, K.sub.2 HPO.sub.4 1.0 g,
MgSO.sub.4.7H.sub.2 O0.5 g, KCl 0.5 g, FeSO.sub.4.7H.sub.2 O 0.01 g, bacto
agar 15.0 g, distilled water liter). The microorganism grows well at room
temperature (25.degree. C.) on most of the laboratory media. On YMG agar
(yeast extract, malt extract, glucose, agar; 4:10:4:18 grams per liter in
distilled water), it produced slightly wrinkled colonies that were
yellowish orange with abundant aerial hyphae at the periphery. The growth
was powdery on N.Z. Amine-A (NZ amine-A 3 g in liter distilled water) agar
and leathery on nutrient agar (Difco, Detroit, Mich.). Older colonies
developed cracks typical of Nocardia autotrophica. During the microscopic
examination, the aerial as well as substrate hyphae appeared straight with
branchings at right angles. Spirals, sporangia, spore chain or endospores
were not seen. The microorganism decomposed adenine, tyrosine,
hypoxanthine, xanthine, and casein. It produces acid with adonitol,
cellobiose, glucose, galactose, inositol, lactose, maltose, mannitol,
melibiose, a-methyl-D-glucoside, raffinose, trehalose, and xylose. Acid
production was not observed with arabinose, erythritol, melezitose,
rhamnose, and sorbitol.
Although the colonial morphology of ATCC 53668 was similar to that of N.
autotrophica, its physiological characteristics were closer to those of
Streptomyces griseus. Consideration of these two major traits warranted
recognition of this strain as a new variety of S. griseus. The
nomenclature, S. griseus var. autotrophicus var. nov. was adopted.
SPECIFIC DESCRIPTION
The following Examples 1 to 6 show the preparation, identification and
testing of the nitrophenyl pyrone compounds used in the method of the
present invention. The method used herein is by means of fermentation
using various species of Streptomyces.
EXAMPLE 1
MN-2-147A, . MN-2-156A and MN-2-156B nematocidal/mosquitocidal compounds
were isolated and purified from the fermentation broth of S. griseus var.
autotrophicus ATCC 53668 as shown in FIG. 1. Modifications in the
fermentation medium and conditions for S. griseus, a previously reported
isolate which produces faeriefungin antibiotic in Ser. No. 177,311,
resulted in the production of MN-2-147A. Less molasses was used in the
regular A-9 medium to obtain the modified A-9 medium (A-9 regular, Peptone
5g, glucose 10g, molasses 20g/L; modified A-9, peptone 5g, glucose 10 g
and molasses 10-15 g/L). Fermentation was carried out in a modified Bellco
15 L glass fermentor (two side baffles opposite to each other on the side
of the fermentation flask). The fermentation conditions were: 7 days,
26.degree. C., air flow 40 psi, stirrer speed 800-900 rpm, 1 ml silicone
oil anti-foam added twice at 24 hour and 12 hour intervals. The
processing of MN-2-147A was as shown in FIG. 1.
MN-2-147A was isolated as an orange-yellow solid, recrystallized from MeOH,
gave melting point at 74.degree.-75.degree. C. (reported closely related
spectinabilin has a melting point 91.degree.-92.degree. C.); UV maxima at
365 (7528), 267 (9788), 251 (9747), 212 (12692) and 202 (16943) nm in
EtOH. The reported UV maxima for spectinabilin 367 (15,500), 268 (18200),
252 (17600), 218 (19100) nm in EtOH. The extinction values for MN-2-147A
were about half the extinction values for spectinabilin. .sup.1 H and
.sup.13 C-NMR spectra indicated MN-2-147A and MN-2-155D, isolated from
Streptomyces spectinabilis, are optical isomers. The compound MN-2-147A
was identified to have the structure as follows:
##STR4##
EXAMPLES 2 TO 4
In a like manner nitrophenyl pyrones MN-2-155D, MN-2-156A and MN-2-156B
were isolated from strains of Streptomyces obtained from the American Type
Culture Collection (ATCC) as follows:
Streptoverticillium mobaraense ATCC 25365
Streptomyces spectinabilis ATCC 27465
and the nitrophenyl pyrones isolated using the method set forth in FIG. 1
and in Example 1. The compounds isolated were as shown in Table 1.
TABLE 1
______________________________________
List of Streptomyces strains and metabolites,
the nitrophenyl pyrones and nematocidal and mosquitocidal
activities when fermented in A-9 medium.
147A 155D 156A 156B
______________________________________
Streptomyces griseus var
* -- * *
autotrophicus ATCC 53668
Streptomyces luteoreticuli,
-- -- * *
ATCC 25365
(Streptoverticillium mobaraense)
Streptomyces spectinabilis,
-- * --
ATCC 27465
Streptomyces nigellus subsp.
-- -- -- --
africanus, ATCC 31496
Streptomyces nigellus,
-- -- -- --
ATCC 27450
______________________________________
Table 2 shows the nematocidal activity of the crude extracts obtained by
the method of FIG. 1.
TABLE 2
______________________________________
Nematocidal activity of crude extracts (3h)
Concentration in .mu.g/ml
1 4 40 80 160
______________________________________
27465A -- -- * ** all dead
27465B -- -- -- -- --
MN-2-147A
all dead all dead all dead
all dead
all dead
25365 -- -- all dead
all dead
all dead
Control -- -- -- -- --
______________________________________
-- no activity
* 30% dead
** 60% dead
EXAMPLE 4
Based upon the results of the tests shown in Table 2, the compounds 155D,
156A and 156B were identified based upon .sup.1 H-NMR, .sup.13 C-NMR,
melting point, ultraviolet spectra and mass spectra. The data for the
identification of Compound MN-2-147A is also set forth. The results are
shown in Tables 3 to 5 and in FIG. 2 to 7.
TABLE 3
______________________________________
.sup.1 H-NMR Chemical Shift Values and Their Assignments
______________________________________
MN-2-155D
MN-2-147A Multiplicity Assignment
______________________________________
8.16 8.14 d, J=9Hz 19, 21
7.43 7.38 d, J=9Hz 18, 22
6.45 6.41 s 16
6.07 6.03 s 10
5.95 5.91 s 14
5.83 5.78 s 12
5.11 5.07 t, J=6.6Hz 7
4.76 4.66 qb, J=13Hz 9a
3.93 3.87 s 2a
2.97 2.85 dq, J=6.4, 15.7Hz
8
2.08 2.04 s 15a
2.03 1.98 s 13a
2.02 1.94 s 5a
1.99 1.92 s 11a
1.84 1.76 s 3a
______________________________________
MN-2-156A MN-2-156B
ppm multiplicity assignment
ppm multiplicity assignment
______________________________________
8.19 d, J=9Hz H-13, H-15
8.15 d, J=9, dHz
H-15, H-17
7.45 d, J=9Hz H-12, H-16
7.36 d, J=9Hz H-14, H-18
7.1 s H-10 6.33 s H-12
6.57 s H-7 6.17 s H-10
6.25 s H-8 5.11 t, J=6.2Hz
7
3.93 s 4a 4.76 q, b, J=13Hz
9a
2.14 s 9a 3.91 s 2a
2.11 s 5a 2.97 dq, J=6.4,
8
15.7Hz
1.95 s 3a 2.00 s 5a
1.99 s 11a
1.80 s 3a
______________________________________
TABLE 4
______________________________________
.sup.13 C-NMR Chemical Shifts and Their Assignments
______________________________________
Position MN-2-155D MN-2-147A
______________________________________
4 181.26 180.47
2 162.73 162.00
6 155.68 155.03
20 146.52 145.70
17 145.32 144.61
15 140.02 139.33
9 138.40 137.64
13* 136.25 135.54
12 135.94 135.19
14 135.03 134.28
11* 134.57 133.83
18 130.16 129.41
22 130.12 129.40
16 128.79 128.01
10 127.42 126.72
19 124.19 123.39
21 124.10 123.36
5 120.61 119.78
3 100.57 99.74
7 77.24 73.11
9a 73.84 69.98
2a 55.90 55.16
8 38.88 38.11
13a 20.27 19.48
15a 20.13 19.34
11a 18.51 17.72
5a 10.08 9.31
3a 7.56 6.80
______________________________________
Position MN-2-156A Position MN-2-156B
______________________________________
4 166.28 4 181.20
2 165.35 2 162.73
6 160.24 6 155.33
14 146.88 16 146.66
11 144.50 13 144.91
9 139.08 11 141.31
8 136.52 10 141.30
7 131.36 9 139.29
12 130.42 14 130.25
16 130.40 18 130.21
10 127.69 12 128.97
13 124.25 15 126.63
15 124.23 17 124.17
5 103.67 5 120.77
3 94.16 3 100.56
4a 56.86 7 73.93
9a 19.82 9a 70.75
5a 14.96 2a 55.92
3a 9.40 8 38.87
11a 18.37
5a 10.08
3a 7.54
______________________________________
*Assignments can be interchanged.
TABLE 5
______________________________________
m.p.
______________________________________
MN/2/155D 107-102.degree. C.
MN/2/156A 164-165.degree. C.
MN/2/156B 157-158.degree. C.
MN/2/147A 74-75.degree. C.
______________________________________
Based upon this data, the following structures were determined.
##STR5##
Compound MN-2-156A is a new compound which has not been described in the
literature. It does not contain the furanyl group which is present in
aureothin and spectinabilin. It is noted that the new spectinabilin (147A)
has a much different melting point than the reported spectinabilin (155D).
It was concluded that compound 147A was an optical isomer of
spectinabilin.
EXAMPLE 5
The nematocidal activity of the purified compounds of Examples 1 to 4 was
determined. The results are shown in Table 6.
TABLE 6
______________________________________
Nematocidal activity of the Streptomyces metabolites
Concentration
in ppm 147A 155D 156A 156B
______________________________________
10 D D D D
1 D D 90% D D
0.1 90% D slow 90% D 90% D
0.01 Ok Ok adults D
Ok
young Ok
CTL Ok Ok Ok Ok
______________________________________
D = 100% kill. Ok = no effct. CTL = control.
At 24 hours (0.1 ppm.) all the test compounds gave 100% mortality. At 0.1
ppm some young nematodes were alive for 155D and 147A at 24H. The above
experiment was conducted in triplicate. Nematodes used were: C. elegans,
P. redivivus, and H. glycines.
EXAMPLE 6
The mosquitocidal activity of the compound of Examples 1 to 4 was
determined. The results are shown in Table 7.
TABLE 7
______________________________________
Mosquitocidal activity of Streptomyces metabolites.
Concentration
in ppm 147A 155D 156A 156B
______________________________________
62.5 D 60% D D D
6.25 D 80% D 60% D D
CTL O O O O
______________________________________
D = 100% killed. At 24 hours, 155D and 156A gave 100% kill. The mosquito
larvae used were Aedes egyptii.
Table 6 shows that the compounds of Examples 1 to 4 are particularly
effective on nematocides in the range between 0.01 and 10 ppm. Table 7
shows that the compounds of Examples 1 to 4 are particularly effective at
dosages between abut 6 and 63 ppm. Effective dosages between about 0.001
and 100 ppm are preferred for the compounds of Examples 1 to 4. As can be
seen, there are different activities for the compounds within this range.
It will be apparent from the differences in the claimed structures of the
isolated nitrophenyl pyrones that there are a wide variety of such
compounds that are effective as insecticidal compounds. Numerous compounds
will occur to those skilled in the art which can be derived synthetically
rather than by the use of microorganisms.
It is intended that the foregoing description be only illustrative of the
present invention and that the present invention be limited only by the
hereinafter appended claims.
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